Continuous curb-forming machine

ABSTRACT

There is provided a curb-casting machine particularly useful in continuously casting high column concrete forms and which is characterized by a novel multistaged open-ended slip-form. The slip-form is carried upon a movable frame which is desirably, although not essentially, adjustable, which is in turn supported on a carrying frame. Locomotive means are provided for moving the carrying frame along a surface on which the casting is being laid.

United States Patent Walker 1 May 30, 1972 s41 CONTINUOUS CURB-FORMING 3,098,414 7/1963 Guntert ..94/46 R MACHINE 1,191,731 7/1916 Ransome ....2s/32 3,363,523 1/1968 Brock ....94 48 1 Invenwfl Robe" Walk", Shaker "fights, Ohm 1,163,770 12 1915 Ransome ..94/46 R Assig ee Medusa Cement C p y l Guntel't Cl 1 dH hts,Oh'

eve an elg 10 Primary E.raminerJacob L. Nackenofi [22] Filed: Aug- 17, 1970 Attorney-McNenny, Farrington, Peame and Gordon [21] Appl. No.: 64,251 ABSTRACT There is provided a curb-casting machine particularly useful US. Cl in Continuously casting g column concrete forms and which Fie'ld of Search 94/46 46 3/ 43 25 is characterized by a novel multistaged open-ended slip-form. 25/138 P 131 The slip-form is carried upon a movable frame which is desirably, although not essentially, adjustable, which is in turn supported on a carrying frame. Locomotive means are pro- [56] References cued vided for moving the carrying frame along a surface on which UNITED STATES PATENTS 6/1968 Ruggles ..94/46 R the casting is being laid.

6 Claims, 13 Drawing figures Patented May 30, 1972 6 Sheets-Sheet 2 INVENTOR. ROBERT WALKER rllllllllll-llllllll 4| 7mm WW 5 W A TTORNEYS Patent ed May 30, 1972 6 Sheets-Shut 3 INVENTOR. ROBERT WALKER "Tog/lanai 4T1 mvsvs Patented May 30, 1972 3,665,821

6 Sheets-Sheet 4 INVENTOR.

ROBERT WALKER INVENTOR.

ROBERT WALKER A ORNEYS 6 Sheets-Sheet 5 Patented May 30, 1972 i ll Patented May 30, 1972 6 Sheets-Sheet 6 INVENTOR ROBERT WALKER fiat m 1 1m: {W

ATTORNEYS CONTINUOUS CURB-FORMING MACHINE BACKGROUND OF THE INVENTION AND PRIOR ART In the past 30 years, paving contractors and construction equipment manufacturers have been seeking to increase productivity and reduce labor costs in road building operations. A variety of continuous pavers and curb-fomiing machines are thus available. Typical examples are illustrated by the patents to Smith U.S. Pat. No. 3,137,220, Larsen et al U.S. Pat. No. 3,161,116, Supject U.S. Pat. No. 3,161,117, Canfield U.S. Pat. No. 2,707,422, and Sigmund U.S. Pat. No. 3,208,362. While these machines are capable of satisfactory use in the formation of low column curbing, and combined curbing and gutter surfaces, these cast forms are generally of relatively low profile. The present invention fills a gap in construction methods resulting from the development of concrete median barriers or high column curbs. Concrete median barriers of relatively high profile (e.g. 12 to 48 inches in vertical dimension, hereinafter called high column) are rapidly replacing an infinite variety of guard rails, e.g. corrugated metal rails, for a number of reasons. They are more impervious to damage when impacted by a vehicle. They deflect a careening car back into the same direction traffic lanes with minimum damage to the car or the curb. They prevent cars from entering oppositely directed traffic lanes. They serve as a guide by reflecting light when driving along unlighted highways. They also require minimal maintenance.

Highway departments across the country have been quick to adopt concrete median barriers for curbs, and are presently formulating standard safety shapes. While at the present time there is little uniformity in the standard cross-sections, road building contractors uniformly are constructing these concrete barriers using fixed, usually metal frame, forms placed and removed after the setting period by hand labor.

The present invention replaces this manual operation by means of a self-propelled continuous high column casting machine. These machines eliminate form storage and transportation, form anchor preparation, form placement, form stripping, and form loading and removal by truck from the construction site. It eliminates the high inventory of forms and form hardware. The machines embodying the present invention require no trackage for support or guidance, and they produce a high-quality high-density section, particularly where vibration is utilized to aid in air removal. It utilizes low slump settable compositions for high strength and early setting.

In continuously casting high profile forms, it has been found that it can be done successively when the full height is built up in successive stages. To the achievement of this end, there is provided a multistage slip-form having a pair of fixedly spaced parallel sidewalls of increasing vertical dimension from the leading end toward the trailing end, the increase in. vertical dimension preferably being stepwise, and defining a plurality of successive stages for acceptance of settable material, e.g. concrete mix. There may also be provided a removable trailing section also having fixed parallel sidewalls which are extensions of the surfaces of the final stage. These trailing walls, unlike the forming walls, are of generally constant vertical dimension for troweling the surface as it emerges from the trailing end of the multistage slip-form. While the multistage slip-form desirably has vibrators mounted on the exterior of the sidewalls at each stage, the railing section preferably does not.

As indicated above, concrete safety barriers have previously been cast in place using stationary metal forms which were removed after sufficient concrete setting time and usually on the day following pouring. The placement and removal of fixed forms entails considerable preparation time, man power, and hardware inventory, all of which is substantially reduced by utilization of the present invention. Still further, the surface finish of the concrete barrier produced by fixed forms requires extensive manual troweling to produce an acceptable surface quality. Conversely, barriers formed by utilization of machines in accordance with the present invention are virtually free of surface voids even when using zero slump concrete. The embodiment of an open-ended slip-form as herein described permits the placement of embedded materials and construction joints in advance of the traveling form, the only qualification being the limitation of objects to within the slip-fonn boundaries. In the preferred embodiments of the present invention, the quality and strength of the median barrier may be further enhanced by the positive elimination of entrapped air and improved bonding between the coarse aggregate particles. Variable speed of advance available with these machines permits a wide range of consistencies in the settable material, usually concrete, to be placed.

BRIEF STATEMENT OF THE INVENTION Briefly stated, the present invention comprises an openended multistage slip-form having a pair of fixedly spaced parallel sidewalls of increasing vertical dimension from the leading end to the trailing end and useful in a curb-casting machine for continuously casting high column forms. It is con veniently carried on means for supporting and advancing the form along a predetermined path, and includes means for feeding a settable composition to each of the stages of the slipform. In the illustrated embodiment there is provided a movable frame, vertical adjustment of which is achieved by means of hydraulically actuated jacks. The movable frame is in turn supported on a main carrying frame which is in turn mounted on locomotive means for moving the carrying frame along a predetermined path on a supporting surface. In the illustrated embodiment, the main carrying frame is carried on nondriving drum wheels at the lead end of the machine and hydraulically powered crawlers at the trailing end of the machine. Steering of the apparatus is achieved by metering the oil supply to the crawler hydraulic motors. The main frame may also support an equipment or machinery platform, distribution means, control panels and settable material handling means.

A specific embodiment of the present invention comprises an open-ended slip-form supported on a movable frame to provide vertical adjustment by means of hydraulically actuated jacks. The jacks are mounted on the main structural carrying frame which is supported on nondriving drum wheels at the lead end of the machine and hydraulically operated crawlers at the trailing end of the machine. Steering is achieved by metering the oil supply to the crawler hydraulic motors. The main carrying frame supports a machinery plat form, distribution feeders, electrical and hydraulic control panels, a concrete splitter chute and a concrete belt feeder. A pair of hydraulically powered feeders are located over the leading end of the open-ended slip-form. Located above and between the two feeders is a bifurcated distribution chute with a splitter gate. A concrete mix is fed to the chute by an inclined belt feeder or tripper which is supported adjacent one end by the main frame of the machine and at its opposite end by a caster wheel under a receiving hopper. Transit mixed concrete is fed to the receiving hopper while the curb-casting machine is in motion. The machinery platform in the preferred embodiment supports a diesel engine power plant, hydraulic pumps and oil reservoir, heat exchanger, valve panel, electrical generator for electrical vibrators, and control power, control panels, a water tank, and a pump. The machine movements under locomotion including steering and form elevating and lowering are controlled manually, or automatically controlled by sensors contacting a taut wire or by a surface riding device. A self-contained water supply is carried beneath the machinery platform and by means of suitable pumps is delivered to the concrete feeders or to a hose connection for wash-down. Water metering is achieved through setting of manual valves.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention is illustrated in the annexed drawings wherein:

FIG. 1 is a side elevation of one embodiment of a continuous curb-casting machine of the present invention showing an equipment platform, a lifting frame, a carrying frame, a multistage slip-form, and locomotive means.

FIG. 2 is a top elevation of the machine shown in FIG. 1 and illustrates a tripper for delivering a settable composition from batch supplies thereof to a hopper carried by the machine.

FIG. 3 is a cross-sectional view of the machine shown in FIG. 1 as it appears in the broken plane indicated by the line 3-3 in FIG. 1.

FIG. 4 is a plan view of the lifting frame, the carrying frame and the settable material hopper of the machine shown in FIG. 1 having the equipment platform removed, and generally as the machine appears in the plane indicated by the line 4-4 in FIG. 1.

FIG. 4a is an end view of the trailing end of the machine shown in FIG. 1, and showing the trailing end of the slip-form.

FIG. 5 is a fragmentary cross-sectional view of the machine as it appears in the plane indicated by the line 55 in FIG. 1 and showing lifting jacks for raising and lowering the lifting frame which supports the multistage slip-form.

FIG. 6 is a side elevation of a multistage, open-ended slipform of the present invention, and showing supporting columns for attachment to the lifting frame of FIG. 4.

FIG. 7 is a plan view of the slip-form shown in FIG. 6.

FIG. 8 is an end view of the slip-form shown in FIG. 6.

FIG. 9 is a cross-sectional view of the slip-form in one of its stages as it appears in the plane indicated by the line 99 in FIG. 6.

FIG. 10 is a cross-sectional view of the slip form in another of its stages as it appears in the plane indicated by the line 10-10 in FIG. 6.

FIG. 11 is a cross-sectional view of the slip-form in still another of its stages as it appears in the plane indicated by the line lI-1l in FIG. 6.

FIG. 12 is a cross-sectional view of a concrete curb or divider for a highway produced by the machine illustrated in FIGS. 1 11 inclusive.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now more particularly to FIGS. 1 5 inclusive, FIGS. 1, 2 and 3 illustrate a general arrangement of the apparatus, including the multistage slip-form hereof. There is provided a main structural carrying frame 10 adapted to support above it a rectangular movable frame 12 and an equipment platform 14. Suspended from the movable frame 12 by means of a plurality of columns 16 is a multistaged openended slip form generally indicated at 18. The front or leading end of the main structural carrying frame 10 is supported by means of struts 20 and 22 which support on an axle 24 a nondriving drum wheel 26. Locomotion for the apparatus is provided by a crawler 28 of known and commercially available structure. Right and left crawlers 28 are provided, details thereof being best illustrated in FIG. 3.

In the embodiment shown, there is provided a diesel engine 30 mounted on the equipment platform 14 adapted to drive a generator 32 to provide electrical power. The drive shaft 34 is also adapted to drive hydraulic pumps 36, 38, 40 and 42 for operating the hydraulic motors controlling the concrete feeder belt conveyor 44, the crawler hydraulic motors 46 and 48, the screw conveyor motors 136 and 138, and the lifting motors 51 and 52 for the hydraulic lifting jacks 54, 56, 58 and 60. Actuation of the motors 51 and 52 causes vertical movement upwardly or downwardly of the movable frame 12 to raise or lower the slip-form 18.

The equipment platform 14 also supports an oil reservoir 62 for storage of the hydraulic fluid, said reservoir having a manual control manifold 64 thereon. There is also provided an oil-to-air heat exchanger 65 for cooling the oil in the hydraulic system. Motor 67 drives a fan for moving air through the heat exchanger 65. An electrical control panel 66 is also provided. Suspended beneath the equipment platform 14 is a fuel tank 68, and a water tank 70 for storage of service water and water for washing the equipment for handling the settable material. A water pump 72 co-operates in a water line to move water from the tank to a point of discharge. A battery 74 for the diesel engine is also suspended from the equipment platform 14 for service lights and ignition of the diesel engine 30. An opening 76 is provided in the floor of the otherwise rectangular equipment platform 14 in the forward right-hand section thereof to provide access to concrete feeder hoppers 78 and 80.

The belt conveyor 44 is part of a tripper generally indicated at 82 suitably supported on the main structural carrying frame 10 and mounted at its outer end on a caster 85. Adjacent the outer end of the tripper 82 is a loading hopper 84 for reception of transit mixed concrete from a truck while the casting machine is moving along a predetermined path. The conveyor belt 44 is reeved around a driven pulley 86 and a head pulley 88 disposed for discharge of freshly mixed concrete into a bifurcated discharge chute 90'having a forward leg 92 and a rearward leg 94 for discharge into concrete feeder hoppers 80 and 78, respectively. A splitter or flop gate 96 controls the flow of transit mixed concrete into the hoppers 78 and 80, and is adjustable manually by the operator. Suitable guard rails 98 and 100 are provided for the safety of the operator.

Referring now more particularly to FIG. 3, there is here shown in greater detail the movable frame 12 and the concrete feeder hoppers 78 and 80. The concrete feeder hoppers 78 and 80 are arranged for coaction with each of the three stages of a three-stage multistaged open-ended slip-form 18. A sloped divider 102 separates concrete feeder hopper 78 from concrete feeder hopper 80. Extending through the lower portion of each of the hoppers and adjacent the apex of the converging sides 104 and 106 is a shaft 108 having screw conveyor flights 110, 112, and 114 spirally disposed about the shaft for urging transit mixed concrete toward the discharge openings 1 16, 118 and 120 coacting with the first, second, and third stages of the open-ended slip-form 18 as hereinafter more particularly described. The shaft may also be provided with axially spaced mixing paddles 122, I24, 126, 128, 130, 132, and 134. In the embodiment shown in FIG. 4, stages 1 and 2 of the slip-form 18 are fed from a common hopper and, to this end, the screw conveyor flight 112 is a right-hand screw, and screw conveyor flight 114 is a left-hand screw. Motive power for driving the screw conveyors 110, 1 l2, and 114 is provided by motors 136 and 138 operating through a chain drive from drive sprockets 140 and 142 to driven sprockets 144 and 146. Driven sprockets 144 and 146 are keyed to the shaft 108. Motors 136 and 138 are conveniently hydraulic mo tors.

To improve the flow of the concrete mix, the concrete feeder hoppers 78 and 80 are conveniently provided with vibrators such as vibrators 148 and 150 to impart an oscillatory motion (60 cps) to the sidewalls of the hopper. Vibrators are provided on one side of each of the hoppers 78 and 80 as shown in FIG. 1 although two pairs of oppositely disposed vibrators may be conveniently employed for this purpose in conjunction with the concrete feeder hoppers 78 and 80, if desired.

The concrete hoppers are conveniently mounted on crossbeams 152, 154, 156, 158, and within the main structural frame 10. A wash water line 162 is also provided for washing the hoppers 78 and 80 and adjusting the water content of the concrete mix. Removable sloping cover plates 164 and 166 Y may also be provided. A divider or removable cap 168 separates the concrete hopper 78 from the hopper 80. Divider plates 170 and 172 isolate the lower compartment of hopper 78 from the lower compartment of hopper 80, and suitable bushing and sealing means generally indicated at 174 and 176 are provided.

The movable frame 12 is desirably and conveniently rectangular in configuration and formed from side members 178 and 180, the end members 182 and 184, and an intermediate cross member 186. The opening defined by side members 178 and 180, cross member 186, and forward end member 184 is dimensioned to receive wholly within its inner boundaries the periphery of the hoppers 78 and 80 as they are arranged and shown in FIG. 4. The movable frame 12 is provided at its opposite ends with vertically extending guide members 188, 190, 192, and 194 suitably secured as by welding to the end members 182 and 184 in suitable mounting brackets 196, 198, 200, and 202. The guide members include elongated pins or dowels 204, 206, 208, and 210, respectively, which are adapted to extend through and be guided by guide collars such as guide collar 212. The guide collars are supported by suitable brackets, such as bracket 214, secured to the main structural carrying frame 10.

Movement of the movable frame 12 in a vertical direction is achieved in the embodiment shown by means of elongated lead screws 216, 218, 220, and 222 depending from locations adjacent each of the comers and fixedly secured thereto. Lines lying in a common plane and joining the vertical axes of the lead screws 216, 218, 220, and 222 define a right rectangle. Drive worms 224 and 226 coacting with captive nuts (not shown), as in a conventional screw jack, are joined by a drive shaft 228 and are on a common axis for coaction with vertically extending screws 220 and 222, respectively. The worm drives 224 and 226 are driven by a hydraulic motor 52. An extension 230 of the drive shaft 228 transmits rotatory motion through a right angle gear box 232 mounted on the main structural carrying frame 10. The structure of the jacking mechanism at the trailing end of the movable frame 12 is identical with that immediately above described for the leading end of the movable frame 12. Accordingly, it includes the lead screws 216 and 218 secured to the movable frame and elevated by means of worm drives 234 and 236 also coacting with captive nuts (not shown), joined by drive shaft 238, and driven by hydraulic motor 51. An extension 240 of the drive shaft 238 extends through a right angle gear box 242. Jack shaft 244 coacts between gear boxes 232 and 242 to synchronize the rotation of drive shafts 228 and 238 so that the movable frame 12 is elevated uniformly at both extremities.

Secured to and depending from the movable frame 12 is a plurality of lifting posts, such as posts 16; and a corresponding set of posts 16 for the opposite side of the open-ended slipforrn is also provided but not shown. In the embodiment illustrated, the mode of securement of the posts or columns 16 to the movable frame 12 includes a column clevis 246 and a frame clevis 248 welded respectively to the column and the frame. A rod 250 coacts with clevis pins 252 and 254 extending through eyes in the ends thereof to support the upper end of the column and allow for slight lateral movement of the posts 16 relative to the frame 12. To stabilize the columns 16, sleeves 256 welded to the main structural carrying frame impart the stability of the main structural frame to the posts and serve as guides for the posts during movement of the movable frame 12 upwardly and downwardly.

The lower ends of the columns 16 are secured through suitable brackets 258 as by welding, the brackets being, in turn, fastened by any suitable means, e.g. bolts 260, to formers or external bulkheads 262 constituting a part of the slip-form 18 (FIG. 4a).

Accordingly, by actuating hydraulic motors 51 and 52, the movable frame 12 and the depending columns secured thereto and in turn the open-ended slip-form 18 may be moved in a vertical direction upwardly or downwardly as desired.

Referring now more particularly to FIGS. 6 11 inclusive, there are here shown details of the construction of a multistaged open-ended slip-form constituting a novel element of this invention. The illustrated slip-form is provided with three stages. It will be understood, however, that depending upon the geometric configuration of the cross-section of the concrete curb or divider to be cast, two or more stages may be used. The slip-form is a built-up structure including stepped sidewalls 264 and 266. The sidewalls 264 and 266 may be a single sheet of metal, or a plurality of sections may be fastened together to provide the entire forming wall surface. The sidewalls 264 and 266 are supported in fixed parallel opposed relation by means of external bulkheads, e.g. bulkheads 262, 268, and 270, which provide support and rigidity to the structure, and also provide attachment points for the columns 16 as previously described. As indicated, the slipform of FIGS. 6 11 is a tri-stage device. The first stage is shown in cross-section in FIG. 9. Sidewalls 264 and 266 as shown in FIG. 9 include removable marginal edge-forming portions 272 and 274 and upwardly and inwardly extending shoulder-forming portions 276 and 278. The angularly related parallel marginal edge-forming portion 272 and shoulderfonning portion 276 on the left side as viewed in FIG. 9, and the portions 274 and 278 similarly and oppositely angularly related constitute a base forming portion for the final cast divider strip. As shown in FIG. 7, the sidewalls 264 and 266 are relatively widely spaced apart in this region, said sidewalls 264 and 266 including outwardly and downwardly flaring marginal edges 280 and 282 toward the leading edge of the form. The bottom edges 284 and 286 of the marginal edge-forming portions 272 and 274 are adapted to ride on or be carried closely adjacent the casting supporting surface or grade line, e.g. a prepared gravel bed or a previously formed foundation.

Transition from the first stage to the second stage occurs by slopingly increasing the width of the sidewalls 264 and 266 along rearwardly raked edges 288 and 290. The cross-sectional configuration of the sidewalls 264 and 266 in the second stage is as shown in FIG. 10. It will be observed that shoulderforming portions 276 and 278 (FIG. 9) have been extended in the same direction to fill out the sides of the curbing or divider strip.

The third stage of the slip-form 18 provides the cap portion for the cast form wherein the sidewalls 264 and 266 are now provided with angularly related cap-forming portions 292 and 294 which converge somewhat less abruptly than the shoulder-forming portions 276 and 278. The transition from the second stage is provided by rakes edges 296 and 298 to the ultimate upper marginal edges 300 and 302 for the openended slip-form 18. It will be observed that the upper marginal edges of the sidewalls 264 and 266 are spaced apart and in stepwise manner approaching each other from the leading end of the form 18 toward the trailing end of the form 18 (left end in FIG. 7). The space between these upper marginal edges provides for the admission of unset transit mixed concrete from the discharge openings 116, 118, and (FIG. 1), the said openings being dimensioned at their exit extremities to direct the flow of plastic concrete between the upper marginal edges of sidewalls 264 and 266.

It will be found convenient for admission of concrete into the third stage to provide flared inlet lips 301 and 303 on the upper marginal edge 300 opposite the concrete discharge outlet 120.

With more particular reference to FIG. 4a, it will be observed that vibrators have been mounted on the opposing sidewalls 264 and 266. Those illustrated in FIG. 4a in dotted lines are mechanical-type vibrators utilizing an eccentric member driven by an electric motor. For best result, vibrators are mounted opposite each of the three stages for coaction with the sidewalls to aid in removal of entrapped air or gases in the cast concrete prior to setting. This improves materially the nature of the casting and its setting characteristics. cps vibrations are conveniently used for the stages in the slipform. First stage mechanical vibrators are indicated at 304 and 306, second stage vibrators are indicated at 308 and 3 l0, and third stage vibrators at 312 and 314.

Under some circumstances it is desirable to provide a final or troweling stage 320 which is attached to and trails the multistage open-ended slip-form 18. In the troweling stage 320, the sidewalls, e.g. sidewall 322, are again fixed and parallel and have surfaces which are continuations of the surfaces in the final stage of the slip-form 18. Thus, the sidewalls of the trailing section are each dimensioned and configured for traveling engagement with the lateral surfaces of the cast form. The height of the trailing section is generally constant in contra-distinction to the variable height of the portions of the sidewalls in the multistage slip-form, which sidewalls are effective for molding the settable material. Generally, no vibration is provided in the troweling or trailing section. As indicated below, in normal operation a slight excess of settable material is introduced into the final stage. To adjust the level of the cap or crown portion of the cast form, there is conveniently provided a horizontally disposed screed 324 or strike board across the upper marginal edges of the sidewalls of the troweling section, which screed smooths and removes any excess concrete mix. The mode of support of the trailing section from the movable frame 12 is also by means of columns 16. The external bulkheads for the trailing section are shaped similarly to those in the final stage of the slip-form. Utilization of the trailing section aids in providing a troweled surface to the cast form and is an optional attachment to the apparatus. I

As indicated above, the cross-sectional configuration of the cast article may be varied in accordance with predetermined specifications, e.g. as such specifications may be determined by local, state or federal regulations. In high column castings of the type herein described for concrete dividers, three stages of the slip-form are preferred.

FIG. 12 shows a cross-section or profile of a continuous curb or divider strip formed by the apparatus illustrated by FIGS. 1 l l inclusive. The concrete section 316 is of predetermined configuration and is conveniently provided with anchor pins 318 at spaced intervals.

For a 32 inches high curb or divider having a base about 30 inches wide with a cap 6 inches wide at the top, the slip-form is provided with three stages and a trailing section. The overall length of the slip-form and trailing section is about 30 feet and the forward speed is about 2 feet per minute, and using a low slump concrete mix.

OPERATION OF THE MACHINE The formation of median barriers or dividers may be required on existing paved highways or on new roads which have not yet received paved surfaces. The operation of the machine is identical in either case, the principal difference being in the elevation of the bottom edge of the slip-form. This difference is accounted for by raising or lowering the level of the slip-form with the hydraulically actuated jacks as above described. When pouring median barriers on unfinished roads, the full depth of the form is utilized. When pouring barriers on existing finished roads as a grade line, the bottom edges, e.g. edges 272 and 274, formed by right angle plates, are unbolted and removed from the slip-form l8 and the shallower multistaged slip-form l8 utilized.

The machine is driven to a starting position, aligned and stopped. Sensors (not shown) are extended contacting a taut wire and referenced for automatic operation. The slip-form is lowered to the required elevation and sensors (not shown) set for automatic control and operation. The screw conveyors and the belt feeder of the tripper are started, and the water pump 72 turned on with zero delivery to the screw feeders. The rate of machine travel and the rate of concrete feed are predetermined and controls set accordingly.

For maximum production, machine speed along the predetermined path should be selected for maximum speed consistent with the formation of a stable concrete cast form and acceptable clean-up and finishing qualities.

Concrete mix is discharged from a transit mix truck into the receiving hopper of the inclined belt feeder or tripper. Flow of concrete, which is divided at the belt feeder discharge hopper by an adjustable splitter gate to deliver the proper proportion of concrete to the leading and trailing screw conveyors is directed in full to the trailing screw conveyor at start-up to build a full section starting wall before advancing. The rear vibrators are started and the machine advanced slowly while readjusting the splitter gate to divert part of the flow to the forward screw feeder.

Once forward movement has started, the remaining vibrators on the slip-form are turned on and the rate of advance of the machine brought up to requirements gradually. The receiving hopper on the belt feeder and the screw conveyor troughs are maintained approximately three-fourths full to ensure against starving the moving form. Additional vibrators attached to the screw conveyor troughs or concrete discharge hoppers assist in the flow of concrete through the concrete shuts 116, 118, and 120. These are started prior to pouring any concrete. Water supply and piping headers are activated, if necessary, to provide water addition to the concrete mix. The manual gate on the belt feeder hopper at the lower end of the tripper is set to allow a maximum rate of flow of concrete mix on the belt feeder without spilling over the sides of the belt.

Upon completion of a days operation, the machine will normally be left in a position to resume operation on the following day. The parked position under these circumstances will be with the trailing section 320 of the form raised in place over the last section of formed concrete so that a starting wall is available for the next day's pour.

The formation of a high column divider strip is accomplished in four steps. A partial section approximately 6 inches high is continuously poured in the front section of the open form. This section is fed from the forward discharge opening 116 by the screw feeder. Entrapped air is removed by means of vibrators set on each side of the low profile section, i.e. the first stage. As the machine advances, an additional 12-inch depth of concrete is fed through the second discharge spout 118 by the screw feeder. This lift is also vibrated from both sides to remove air and wet the aggregate surfaces for improved bonding. The advancing machine discharges a third lift (third stage) approximately 18 inches high through the third discharge spout 120. Vibration is also induced in this section which removes air and further compacts the concrete mass lowering the surface level to approximately one-half inch above the finished height. The advancing machine pulls the trailing section 320 of the fonn without vibration over the filled section providing a troweled finish to the sides. A screed 324 located at the top of the form finishes the top surface to the finish dimension. The trailing section 320 is sufficiently long to permit concrete set-up with negligible slump upon emergence from the rear of the form.

Clean-up of extruded concrete at the base and minor surface touch-up is accomplished manually within a 2-hour time limit after pouring without difficulty.

What is claimed is:

l. A curb casting machine for continuously casting high column forms comprising in combination:

a. an open-ended traveling slip-form to compact concrete, wide at the base and with successively narrower portions towards the top, having sides which are in stepped vertical relationship, said narrower portions being of increasing height converging upwardly and in stepped horizontal relationship converging rearwardly;

b. means for supplying a settable material to the forward portion of said converging form, whereby said material is compacted rearwardly and upwardly as the form moves forward.

2. The apparatus of claim 1, including in addition means for vibrating said form.

3. The apparatus of claim 1, including means for lowering and raising said form.

4. The apparatus of claim 1, including oppositely directed screw conveyor means for supplying said settable material.

5. The apparatus of claim 1, including guide means for following a predetermined path.

6. The apparatus of claim 1, wherein said settable material is concrete. 

1. A curb casting machine for continuously casting high column forms comprising in combination: a. an open-ended traveling slip-form to compact concrete, wide at the base and with successively narrower portions towards the top, having sides which are in stepped vertical relationship, said narrower portions being of increasing height converging upwardly and in stepped horizontal relationship converging rearwardly; b. means for supplying a settable material to the forward portion of said converging form, whereby said material is compacted rearwardly and upwardly as the form moves forward.
 2. The apparatus of claim 1, including in addition means for vibrating said form.
 3. The apparatus of claim 1, including means for lowering and raising said form.
 4. The apparatus of claim 1, including oppositely directed screw conveyor means for supplying said settable material.
 5. The apparatus of claim 1, including guide means for following a predetermined path.
 6. The apparatus of claim 1, wherein said settable material is concrete. 